The subject matter disclosed herein relates to a collector monitoring system. Specifically, the subject matter disclosed herein relates to a system for monitoring the condition of collectors used in a dynamoelectric machine (e.g., an electrical generator, electrical motor, etc.), to provide early indication of collector faults.
Conventional dynamoelectric machines include brushes, positioned on a stationary frame, for providing an exciting electrical current during operation of the dynamoelectric machine. The electrical current is directed from the brushes to collectors (e.g., collector rings, or slip rings) coupled to the rotor of the dynamoelectric machine. The collectors then transfer the electrical current to the rotor windings for use in generating power within the dynamoelectric machine. The collectors conduct the electrical current by continuously contacting the brushes during rotation. However, this continuous contact between the brushes and the collectors can be disrupted by: changes in brush pressure due to the wearing of a spring in the brush assembly, vibrations of the dynamoelectric machine shaft, wear to the brush contact surface and/or degradation of the collector film between the collector and the brushes. The disruption of contact between the brushes and the collectors can cause diminished performance in the dynamoelectric machines, and degradation of the brushes and collectors.
Degradation of the brushes and collectors can be minimized, but not eliminated, by establishing and maintaining an optimum electrical contact between the brushes and the collectors. Maintaining the optimum electrical contact depends on a variety of characteristics of the brushes and the collectors, including: maintaining an optimum brush pressure on the collector, lubricating the collector using a collector ring film, maintaining the collector surface condition, and providing the brush with a proper contour fit to the collector. However, maintaining the optimum electrical contact between the brushes and collectors can be challenging. If the electrical contact between the brushes and collectors is too low, sparking and/or arcing may occur. Sparking and arcing significantly increase the likelihood of machine failure due to collector flashovers.
Conventionally, human operators visually inspect brushes and collectors of a dynamoelectric machine to monitor for any collector flashover events. Typically, the dynamoelectric machine is fully operational when the operator inspects the brushes and collectors for any faults. As a result, the human operator is limited in their ability to inspect the dynamoelectric machine for operational faults. Furthermore, prevention of collector flashovers is dependent on the frequency of inspection of the brushes and/or the collectors.